From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Joe Lawrence <joe.lawrence@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
Miroslav Benes <mbenes@suse.cz>,
joao@overdrivepizza.com, nstange@suse.de, pmladek@suse.cz,
live-patching@vger.kernel.org
Subject: Re: CET/IBT support and live-patches
Date: Sun, 5 Dec 2021 22:12:58 -0800 [thread overview]
Message-ID: <20211206061258.df64727kssiil5ed@treble> (raw)
In-Reply-To: <ec0205e5-c974-35d4-651a-f622f44fb84e@redhat.com>
On Wed, Dec 01, 2021 at 01:57:00PM -0500, Joe Lawrence wrote:
> On 11/23/21 4:16 PM, Peter Zijlstra wrote:
> > On Tue, Nov 23, 2021 at 03:58:51PM -0500, Joe Lawrence wrote:
> >
> >> Yep, kpatch-build uses its own klp-relocation conversion and not kallsyms.
> >>
> >> I'm not familiar with CET/IBT, but it sounds like if a function pointer
> >> is not taken at build time (or maybe some other annotation), the
> >> compiler won't generate the needed endbr landing spot in said function?
> >
> > Currently it does, but then I'm having objtool scribble it on purpose.
> >
>
> Hi Peter -- to follow up on the objtool part: what criteria is used to
> determine that it may scribble out the endbr?
ENDBR is "scribbled" for any function for which no function pointer data
relocation exists at vmlinux or module link time.
https://lkml.kernel.org/r/20211122170301.764232470@infradead.org
--
Josh
next prev parent reply other threads:[~2021-12-06 6:13 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <70828ca9f840960c7a3f66cd8dc141f5@overdrivepizza.com>
2021-11-23 9:58 ` CET/IBT support and live-patches Miroslav Benes
2021-11-23 10:48 ` Peter Zijlstra
2021-11-23 11:39 ` Miroslav Benes
2021-11-23 14:10 ` Peter Zijlstra
2021-11-23 16:03 ` Steven Rostedt
2021-11-23 20:40 ` Peter Zijlstra
2021-11-24 10:02 ` Miroslav Benes
2021-11-23 20:58 ` Joe Lawrence
2021-11-23 21:16 ` Peter Zijlstra
2021-12-01 18:57 ` Joe Lawrence
2021-12-06 6:12 ` Josh Poimboeuf [this message]
2021-11-24 10:16 ` Miroslav Benes
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